API (Application Programming Interface) is a set of application programming interfaces provided by applications that allow one-way or two-way interaction between applications that provide the API and third-party applications. The API can use various methods of interaction: from proprietary protocols to standard formats. Queries and return data in HTTP, XML, and JSON formats are often used for making settings and receiving static data. RTSP, ONVIF, and PSIA standards can be used in video surveillance systems. Video can be transmitted in H.264, H.265, MPEG-4, and Motion JPEG formats.